Nicotine is an alkaloid present in plants of the Solanaceae family like the tobacco plant. Apart from nicotine, tobacco leaves also include a complex mixture of compounds which, when burned and inhaled, are associated with serious health conditions, including heart diseases and lung cancer. The role of nicotine in the addiction to tobacco has now been recognized for a few decades.
However, even though the majority of users intend to stop smoking at one point or another, they are all faced with symptoms of withdrawal such as cravings, irritability, weight gain and/or depression when attempting to quit. One treatment to help reduce withdrawal symptoms includes the administration of medication, such as antidepressants or other compounds like varenicline or clonidine, all of which may present secondary effects to various degrees. For instance, the monitoring of patients using antidepressants by a medical professional on a regular basis is highly recommended to promptly identify any adverse effects.
Another approach to reduce withdrawal symptoms consists in what is called nicotine replacement therapy (NRT). In NRT, nicotine is delivered in a form which avoids risks associated with smoking, for instance, transdermally or through the mouth cavity. For instance, NRTs include nicotine patches, gums, mouth and nasal sprays, inhalers, tablets and lozenges. NRTs may also be combined together or with other smoking cessation aids such as medication or counselling.
Among NRTs, nicotine sprays are generally presented as aqueous solutions provided in a bottle which delivers metered doses to the mouth cavity. Absorption of the active is achieved through the oral mucosa. However, nicotine sprays usually also include ethanol, which even in small quantities, may not be suited for all users. Additionally, a burning sensation is often reported by spray users, which could lead to treatment interruption and relapse of the patient. A quicker absorption could also benefit patients in helping to reduce symptoms more spontaneously. There is a need for new formulations which will suit the need of certain populations of users, for instance, being alcohol free, having enhanced absorption and/or having a reduced burning sensation.